1 files changed, 112 insertions, 3 deletions
diff --git a/Lib/importlib/util.py b/Lib/importlib/util.py
index 13164371025..42fc9eae93f 100644
--- a/Lib/importlib/util.py
+++ b/Lib/importlib/util.py
@@ -1,10 +1,18 @@
 """Utility code for constructing importers, etc."""
 
-from ._bootstrap import module_for_loader
-from ._bootstrap import set_loader
-from ._bootstrap import set_package
+from ._bootstrap import MAGIC_NUMBER
+from ._bootstrap import cache_from_source
+from ._bootstrap import decode_source
+from ._bootstrap import source_from_cache
+from ._bootstrap import spec_from_loader
+from ._bootstrap import spec_from_file_location
 from ._bootstrap import _resolve_name
 
+from contextlib import contextmanager
+import functools
+import sys
+import warnings
+
 
 def resolve_name(name, package):
     """Resolve a relative module name to an absolute one."""
@@ -19,3 +27,104 @@ def resolve_name(name, package):
             break
         level += 1
     return _resolve_name(name[level:], package, level)
+
+
+@contextmanager
+def _module_to_load(name):
+    is_reload = name in sys.modules
+
+    module = sys.modules.get(name)
+    if not is_reload:
+        # This must be done before open() is called as the 'io' module
+        # implicitly imports 'locale' and would otherwise trigger an
+        # infinite loop.
+        module = type(sys)(name)
+        # This must be done before putting the module in sys.modules
+        # (otherwise an optimization shortcut in import.c becomes wrong)
+        module.__initializing__ = True
+        sys.modules[name] = module
+    try:
+        yield module
+    except Exception:
+        if not is_reload:
+            try:
+                del sys.modules[name]
+            except KeyError:
+                pass
+    finally:
+        module.__initializing__ = False
+
+
+def set_package(fxn):
+    """Set __package__ on the returned module.
+
+    This function is deprecated.
+
+    """
+    @functools.wraps(fxn)
+    def set_package_wrapper(*args, **kwargs):
+        warnings.warn('The import system now takes care of this automatically.',
+                      DeprecationWarning, stacklevel=2)
+        module = fxn(*args, **kwargs)
+        if getattr(module, '__package__', None) is None:
+            module.__package__ = module.__name__
+            if not hasattr(module, '__path__'):
+                module.__package__ = module.__package__.rpartition('.')[0]
+        return module
+    return set_package_wrapper
+
+
+def set_loader(fxn):
+    """Set __loader__ on the returned module.
+
+    This function is deprecated.
+
+    """
+    @functools.wraps(fxn)
+    def set_loader_wrapper(self, *args, **kwargs):
+        warnings.warn('The import system now takes care of this automatically.',
+                      DeprecationWarning, stacklevel=2)
+        module = fxn(self, *args, **kwargs)
+        if getattr(module, '__loader__', None) is None:
+            module.__loader__ = self
+        return module
+    return set_loader_wrapper
+
+
+def module_for_loader(fxn):
+    """Decorator to handle selecting the proper module for loaders.
+
+    The decorated function is passed the module to use instead of the module
+    name. The module passed in to the function is either from sys.modules if
+    it already exists or is a new module. If the module is new, then __name__
+    is set the first argument to the method, __loader__ is set to self, and
+    __package__ is set accordingly (if self.is_package() is defined) will be set
+    before it is passed to the decorated function (if self.is_package() does
+    not work for the module it will be set post-load).
+
+    If an exception is raised and the decorator created the module it is
+    subsequently removed from sys.modules.
+
+    The decorator assumes that the decorated function takes the module name as
+    the second argument.
+
+    """
+    warnings.warn('The import system now takes care of this automatically.',
+                  DeprecationWarning, stacklevel=2)
+    @functools.wraps(fxn)
+    def module_for_loader_wrapper(self, fullname, *args, **kwargs):
+        with _module_to_load(fullname) as module:
+            module.__loader__ = self
+            try:
+                is_package = self.is_package(fullname)
+            except (ImportError, AttributeError):
+                pass
+            else:
+                if is_package:
+                    module.__package__ = fullname
+                else:
+                    module.__package__ = fullname.rpartition('.')[0]
+            # If __package__ was not set above, __import__() will do it later.
+            return fxn(self, module, *args, **kwargs)
+
+    return module_for_loader_wrapper